sensors Mode-S transponder

39CF03

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-HTYD · AIRBUS A-350-900

Hex
39CF03
Octal
16347403
Decimal
3,788,547
Country
FR
Tail
F-HTYD
Type
A359
Photo of F-HTYD
No current signal · last broadcast 20h ago
Flights observed
7
Distinct callsigns
3
Country
FR
Last broadcast
20h ago

Last known position

Most recent position reported by Mode-S 39CF03.

Country allocation

The ICAO 24-bit address 39CF03 falls within the block assigned to France (FR) by ICAO Annex 10, Volume III. Every aircraft registered in France receives a permanent address from this block at the time of registration; the address stays with the airframe even if the aircraft is re-registered to a different operator within the country.

Callsign history 3 distinct

Callsign Airline Flights Last seen
AFR406 Air France 4 2026-04-14
AFR431 - 2 2026-04-13
AFR430 Air France 1 2026-04-12

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-14 AFR406 CDG → SCL Apr 14, 09:10 UTCApr 14, 09:25 UTC15m
2026-04-14 AFR406 CDG → SCL Apr 14, 07:40 UTCApr 14, 09:05 UTC1h 25m
2026-04-14 AFR406 CDG → SCL Apr 14, 06:15 UTCApr 14, 06:55 UTC40m
2026-04-13 AFR406 CDG → SCL Apr 13, 21:50 UTCApr 13, 23:40 UTC1h 50m
2026-04-13 AFR431 - Apr 13, 09:45 UTCApr 13, 10:45 UTC1h 0m
2026-04-13 AFR431 - Apr 13, 01:50 UTCApr 13, 02:25 UTC35m
2026-04-12 AFR430 CDG → SJO Apr 12, 17:45 UTCApr 12, 18:25 UTC40m

About Mode-S

A Mode-S transponder code (also called an "ICAO 24-bit address" or "hex code") is a 6-character hexadecimal identifier permanently assigned to an aircraft when it's first registered. Unlike callsigns (which change with each flight) or registrations (which can change if an aircraft is sold internationally), the Mode-S address stays with the airframe for the life of the aircraft in that country.

Every ADS-B transmission from an aircraft includes its Mode-S address, making it the most reliable way to identify a specific airframe. Flight-tracking services like Apparatus use the Mode-S address as the primary key for tying position broadcasts, callsigns, and ownership records together.

Prefer a tail-number view? See the F-HTYD page for operator, model, and routing details .

Mode-S 39CF03 frequently asked

What is Mode-S code 39CF03?
39CF03 is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-HTYD.
Where is Mode-S 39CF03 registered?
Mode-S code 39CF03 is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 39CF03 broadcasting right now?
No active broadcast right now. Last signal was 20h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 39CF03, octal 16347403, decimal 3,788,547.
What flights does 39CF03 operate?
Mode-S 39CF03 has broadcast 3 distinct callsigns, including AFR406, AFR431, AFR430.